Method of removal of tool holder in a machine tool

ABSTRACT

A method of removing a tool holder having a protective sleeve and at least one locking element and configured for receiving an insertion tool in a machine tool having a fitting device, includes removing the protective sleeve of the tool holder, complete removal of the locking elements, and separation of the tool holder from the fitting device.

CROSS-REFERENCE TO A RELATED APPLICATIONS

This application is a division application of patent application Ser. No. 10/563,190 filed on Jan. 3, 2006 from which it claims the benefit of priority under 35 U.S.C. 120. The patent application Ser. No. 10/563,190 in turn claims the benefit of priority under 35 USC 119 from German Patent Application 10 2004 036 587.3, filed on Jul. 28, 2004.

BACKGROUND OF THE INVENTION

The present invention relates to a method of removing a tool holder in a machine tool.

Rotary and percussion hammers are provided with fitting devices for insertion tools. They are subject to a relatively great deal of wear resulting from their operation, however. Wear of the driving-element profile of a tool holder is a common cause of failure. The machine tool must then undergo expensive service or it must be scrapped if the repair costs are too high.

SUMMARY OF THE INVENTION

In accordance with the present invention, a method of removing a tool holder having a protective sleeve and at least one locking element and configured for receiving an insertion tool in a machine tool having a fitting device, is proposed that includes removing the protective sleeve of the tool holder, complete removal of the locking elements, and separation of the tool holder from the fitting device.

In accordance with the invention before the removing of the protective sleeve, removing at least one cap can be performed.

In the inventive method, after the removing of the cap, removing at least one ring can be carried out.

In the inventive method, after the removing of the ring, removing at least one disc can be carried out.

Finally, after the removing of the disc, at least one further ring can be removed.

Further embodiments, aspects and advantages of the present invention also result independently of their wording in the claims, without limitation to generality, from exemplary embodiments of the present invention presented below with reference to the drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 Shows a partial cross-section through a transmission region of a preferred power tool;

FIG. 2 Shows a further partial cross-section through a transmission region of a preferred power tool with details of a preferred tool holder;

FIGS. 3 a, b Show a partial cross-section of a tool holder in the installed state (a) and, in an exploded view, they show the steps involved in removing the detachable, preferred tool holder (b).

FIG. 4 A view schematically showing a method of removal of a tool holder from the machine tool in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 through 3 show a preferred tool holder 17 in a fitting device for an insertion tool (not shown) of a preferred machine tool 10 designed as a rotary hammer, in various views.

FIG. 1 shows a partial cross-section through a transmission region of preferred machine tool 10 with a housing 26 and a fitting device located in housing 26, the fitting device enclosing tool holder 17. Tool holder 17 is designed for receiving insertion tools that can be inserted from the side of the fitting device covered with a cap 11.

Tool holder 17 forms a sliding fit 18 with a drive tube 16 designed as a hammer tube, and is partially covered by this drive tube 16. In the region of its free end, tool holder 17 is located inside a protective sleeve 12 that is closed with a cap 11. Two bore holes 13 are shown on the circumference of tool holder 17, which serve to axially fix and non-rotatably connect tool holder 17 with drive tube 16. A total of four bore holes 13 are located on the circumference of tool holder 17. More or fewer bore holes 13 can also be provided, of course. Bore holes 13 are covered by an internal ring 23 of protective sleeve 12. Tool holder 17 is retained with a spring 28 between retaining ring 29 and the end face of drive tube 16, retaining ring 29 bearing against a shoulder of protective sleeve 12 and holding a bearing 30 that is clamped between retaining ring 29 and the shoulder. A gasket 31 is located between tool holder 17 and drive tube 16 on tool holder 17 in the region of sliding fit 18.

A further depiction of tool holder 17 in the inserted position is explained in greater detail in FIG. 2. FIG. 2 shows a further cross section through the transmission region of machine tool 10 in FIG. 1, with details of preferred tool holder 17. Tool holder 17 is connected with drive tube 16 around its outer diameter and forms sliding fit 18 with drive tube 16. A driving-element profile 15 that is susceptible to wear is located inside the tool fitting such that an insertion tool (not shown) extends up to a striking pin 25 of drive tube 16 configured as a hammer tube. The insertion tool can therefore be driven in a rotary and/or percussive manner.

FIGS. 3 a and b show a partial cross-section of the aforementioned tool holder in the installed state at an angle from the front and, in an exploded view, they show the steps involved in removing detachable, preferred tool holder 17.

A locking element 24 is shown close to the free end of striking pin 25, locking element 24 being inserted in a bore hole 14 of drive tube 16 and in bore hole 13—designed as a blind hole—of tool holder 17 such that tool holder 17 is secured axially and non-rotatably with locking element 24, which is accessible from an outer side of drive tube 16. Locking element 24 and/or all four locking elements 24 are contained by inner ring 23 of protective sleeve 12.

As shown in FIG. 3 b, tool holder 17 can be easily removed and, if necessary, replaced. First, cap 11 is pulled off with the elements located behind it, i.e., a ring 20, a disk 21, and a ring 22. Rings 20, 22 are advantageously removed using pliers. It is then possible to remove protective sleeve 12. Locking elements 24 are released as a result, locking elements 24 extending through bore holes 14 of drive tube 16 into bore holes 13 of tool holder 17; they can also be removed using pliers. Tool holder 17, along with spring 28, retaining ring 29, bearing 30 and gasket 31 located thereon, can then be pulled out and replaced, if necessary. Tool holder 17 is a compact unit with spring 28, retaining ring 29, bearing 30 and gasket 31.

Once tool holder 17 is removed, striking pin 25—which is now exposed—can be replaced, along with the no-load operation ring.

FIG. 4 schematically shows the inventive method of removing the tool holder.

In step a, the protective sleeve 12 is removed from the tool holder 17. In step b, a complete removal of the locking elements 24 is performed. In step c, the tool holder 17 is separated from the fitting device.

In accordance with the present invention, in an additional step d, before the removal of the protective sleeve 12, first at least one cap 11 is removed. In an additional step e, after the removal of the cap 11, at least one ring 20 is removed. In step f, after the removal of the ring 20, at least one disc 20 is removed. Finally, in an additional step g after the removal of the disc 21, at least one additional ring 22 is removed. 

1-12. (canceled)
 13. A method of removing a tool holder having a protective sleeve and at least one locking element and configured for receiving an insertion tool in a machine tool having a fitting device, the method comprising the steps of removing the protective sleeve of the tool holder; complete removal of the locking elements; and separation of the tool holder from the fitting device.
 14. A method of removing a tool holder as defined in claim 13; and further comprising, before said removing the protective sleeve, removing at least one cap.
 15. A method of removing a tool holder as defined in claim 14; and further comprising, after said removing the cap, removing at least one ring.
 16. A method of removing a tool holder as defined in claim 15; and further comprising, after said removing the ring, removing at least one disc.
 17. A method of removing a tool holder as defined in claim 16; and further comprising, after said removing the disc, removing at least one further ring. 